Cutting devices are well known in the art. Such devices (scissors, punches, graspers) are generally used in surgery to cut through body tissue in areas of limited access. Conventional surgical scissors are limited by the singular rotational motion of the blades allowing only a shearing action to cut tissue. As a result, there is a tendency for tissue to roll due to the separation of the scissor blades. The blade separation thus impedes cutting and can lead to tissue tearing.
Efforts have been made to solve the aforementioned problems by producing surgical scissors which use a preload on the blades to prevent tissue roll induced by blade separation. The force required to overcome such preloads is frequently greater than the force required to perform a cut. This causes tactile feedback from the actual cutting to fall well below the perception threshold of a surgeon or other user.
Another disadvantage of conventional surgical scissors is that the blades rub against each other resulting in metal against metal blade edge wear. As a result, over time, the blades get dull and must be sharpened or discarded. Efforts have also been made to solve the wear problem of conventional surgical scissor parts by increasing the dimensions of selected parts of the surgical scissors to increase part strengths. However, such efforts have been wholly unsuccessful, in as much as the increased dimensions tend to render the instruments less satisfactory for use in confined spaces.
The present invention overcomes many of the disadvantages inherent in the above-described prior art surgical cutting devices by providing a compound motion cutting device designed to effect a cutting action which is a combination of shearing and cutting, rather than shearing alone, resulting in a slicing motion that more closely approximates the motion of a surgeon's scalpel. The present invention employs a single blade compound motion cutting device including an anvil having a support surface for a work piece with a slot which provides clearance for the blade so that rolling of the work piece as it is being cut is prevented and blade edge wear is avoided to maintain blade sharpness.
The compound motion cutting device of the present invention offers significant improvement in tactile feedback over conventional cutting devices by minimizing blade preload and lowering frictional forces found in conventional steel against steel blades with equal preload. The cutting device of the present invention employs parts which are relatively small in size and are able to function well in confined areas of limited access.